Manually operated valves that have incorporated a lockout/tagout (LOTO) device are known. Two examples of these known valves are designated by reference numerals 1 and 2 in FIGS. 1 and 2 of the drawings. Another example of a manual valve with lockout is disclosed in U.S. Pat. No. 6,463,955 B1.
A pneumatically operated cylinder valve capable of receiving a separate threaded plug for lockout after removing a handwheel of the valve used for valve actuation, is disclosed in U.S. Pat. No. 4,706,909. The valve is not compact enough to fit within a standard cylinder cap, necessitating removal of the handwheel for transport as well as for use of the threaded plug for lockout.
More recently, in published patent application U.S. 2005/570 A1, a combination manual/pneumatic shutoff valve is disclosed wherein a pneumatic valve incorporates an additional manually operated lockout formed with valves for pressurizing and venting the expansion chamber of the pneumatic actuator. Space must be provided for these valves as well as for the air lines and plumbing connected to the valve for pressurizing and venting the pneumatic actuator of the valve. Safety is also a concern with this known shutoff valve as the manual lockout valve for pressurizing could develop a leak, which would pressurize the actuator of the pneumatic valve and open the valve. There is a need for an improved pneumatic valve with lockout which is compact, safe and easy to install.